sodium-24 has a half life of 15 hours. a 1kg sample was left sitting in the laboratory reducing the amount to 244 mg , how long was it left out for

Which states of matter have particles that move independently of one another with very little attraction?

Which of the following is a physical change? a.burning a piece of wood b.sawing a piece of wood in half c.rust forming on an iron fence d.a copper roof changing color from orange to green

Two liquids are poured into a beaker. after a few seconds, the beaker becomes warm. which of the following best describes this reaction? a. an exothermic reaction b. a decomposition reaction c. an endothermic reaction d. a single-displacement reaction